This invention relates generally to an electrical interconnection apparatus and more specifically to an electrical interconnection low insertion force lead socket insert for facilitating the interconnection of leads to an electrical interconnection panel board or socket.
Socket contacts of the type to which this invention relates have been used widely in the industry for the purpose of receiving leads of electronic components. These socket contacts are mounted into pin grid array, dual-in-line and quad-in-line sockets or interconnection panel boards. The socket's contact is generally a two piece construction with the components being a lead socket insert and a machined terminal pin. The lead socket insert is press fitted to the terminal pin providing for a gas-tight interface with the component parts.
Heretofore, known lead socket inserts have been less than completely satisfactory because the converging fingers of the insert have been sized or spread, in effect over stressing the cantilever beam in order to reduce the mating forces. This creates an inherent beam effect in the fingers which causes excessive stress to occur at the fulcrum point of the beam. This condition severely impacts contact reliability during normal operating temperatures where in effect the cantilever beams can become stress relieved. As a result thereof, loss of contact of one or more converging fingers with the component lead can occur. Additionally, the sizing operation of the converging fingers often cause them to be moved into close proximity to each other. This often allows a mating component lead to skew or to penetrate between two of the converging fingers and also limits the size and configuration of the component lead that can be mated to it. This is due to the opened condition of the converging fingers, which will not make consistent contact to leads having a minimum diameter or rectangular cross-section. Accordingly, it is desirable to provide a lead socket insert having improved mating and unmating forces.